This invention relates generally to tillage implements and more specifically to a clamp for attaching the shank of an earthworking tool to a support beam on an implement.
Tillage implements such as cultivators often include an earthworking tool having a shank which is connected to a beam of square or rectangular cross section by a right-angle bracket and a shank bolt. For example, an S-tine shank includes a flat end portion which passes through an aperture in one leg of the bracket and is tightened against one face of the beam by a shank bolt tensioned between the end of the other leg and the flat end portion. Such a prior art connecting or clamp structure is shown in FIG. 1 at 10 and includes a right-angle bracket 12 having first and second legs 14 and 16 positioned against upper and rear faces 18 and 20 of a beam 22 on the tillage implement (not shown). The bracket 12 is fabricated from a flat strip of metal, and the legs 14 and 16 have flat, apertured end portions 24 and 26, respectively, which project beyond the forward and bottom faces 28 and 30 of the beam 22. A shank 32 includes a straight connecting portion 34 extending through the aperture in the end portion 26 and under the face 30. The shank portion 34 includes an apertured end 36 which extends beyond the face 28 directly below the end 24 of the bracket 12. The bracket 12 and shank 32 are secured to the beam 22 by a shank bolt 40 which is tightened to draw the leg 14 and shank portion 34 towards each other and against faces 18 and 30 of the beam 22. An earthworking tool 42 is supported at the lower end of the shank 32 for movement forwardly (arrow F) through the soil.
The prior art structure of FIG. 1 has several shortcomings. The bracket 12 and shank 32 can rotate horizontally on the beam 22 since there is little or no positive clamping of the bracket 12 against the forward face 28 of the beam. If the shank bolt 40 is tightened beyond a preselected tension, the end 24 will begin to bend downwardly. Once the end 24 bends, the bracket 12 is weakened and can no longer effectively be clamped against the beam 22.
To help overcome the lack of positive clamping, some prior art structures include brackets which are similar to that shown at 12 in FIG. 1 but which have end portions 24 formed with downturned tabs or tangs butting against the front face 30 of the beam 22. The tangs are formed by cutting the leg 14 lengthwise on opposite sides of the aperture and bending the edge portions downwardly and parallel to the face 30. Alternatively, both sides of the leg 14 are cut adjacent the front face 30 perpendicular to the lengthwise direction of the leg, and the sides of the end portion 24 are bent downwardly from the horizontal. In either type of tanged structure, the leg 14 is cut so that the cross-sectional area of the leg, and therefore the bending resistance and clamping strength of the leg, is reduced. To increase bending resistance of the tanged structure, the bracket 12 must be fabricated from metal strip having increased cross-sectional area which increases the cost and bulk of the implement.
It is therefore an object of the present invention to provide an improved clamp arrangement for attaching a cultivator shank or the like to a beam.
It is another object of the invention to provide an improved shank clamp arrangement which prevents the shank from rotating horizontally on the supporting beam.
It is another object of the invention to provide an improved shank clamp arrangement which has increased bending resistance and clamping strength as compared with prior art structures of the same size. It is another object to provide such a clamp arrangement with a bracket which has an increased depth of section in the area which receives the shank bolt.
It is a further object to provide an improved clamp arrangement for an S-tine shank. It is yet another object to provide such an arrangement with a bracket having positive clamping structure which obviates cutting of the bracket adjacent the shank bolt aperture.
In accordance with the above objects, a shank clamping arrangement is provided with a bracket having first and second leg portions adapted for positioning against adjacent faces of the mounting beam. The first leg portion includes a formed end portion which receives the shank bolt. The formed portion includes a rounded transition area for wrapping around the edge of the beam to positively clamp the shank and bracket. The transition area is continuous and obviates cutting of the bracket near the shank bolt. The formed end with the continuous transition area provides an increased depth of section to increase bending resistance and clamping strength for a given bracket size.
These and other objects, features and advantages will become apparent from the description which follows when taken with the accompanying drawings.